Patent Application
20070069062
This is a nationalization of PCT/EP2004/004803 filed May 5, 2004 and published in German.
The present invention relates to a winding device according to the preamble of the main claim 1. Winding devices are known from a multitude of published prior art of which only the patent application WO 99/06313 and US 5848761 have been mentioned as examples. Winders are usually categorized as contact winders and turret winders.
Among these winders the following devices must be highlighted here:
The present invention is based on these devices.
In the devices described in the patent applications U.S. Pat. No. 4,852, 820 and DE 102 02 462, the device for electrostatically charging the web-shaped material is used for holding down the web-shaped material on the initial winding sleeve. In this manner it is possible to hold down the initial section of the web-shaped material on a winding core without the help of adhesives. In technical jargon, this method is called “adhesive-free initial winding” and has high economic value because an initial winding process of such type can be executed fully automatically and additionally without the application of solvents on the web-shaped [handwritten correction made to the source; originally said “band-shaped”] material.
As a rule and also in the patent application DE 102 02 462, the afore-mentioned device for electrostatically charging the web-shaped material is usually formed as a beam-shaped electrode that can overcoat the width of the web-shaped material. In all applications and published prior art, they are illustrated in immediate proximity to the winding core and they charge the film with an electrical field when they reach the winding core.
The spatial proximity to the winding core is highly recommended since the strength of electrical fields strongly reduces as the distance from the electrode increases and ideally the biggest possible field effect should be available during the initial winding process. Therefore, the patent application DE 102 02 462 recommends arranging the means for electrostatically charging the web-shaped material as close as possible to the initial winding position, and/or within a small close and constant distance from the winding core during the initial winding process by means of a special displacement of the position of the electrode.
The devices specified in the preamble of the present patent application have proved to be of value during the “adhesive-free initial winding process.” However, like all winding devices of prior art, they exhibit disadvantages during the entire winding and cutting processes when several layers of film or film tubes have to be wound up. In this connection, it must be emphasized that these requirements are by no means unusual because winding devices often wind up the film that is just extruded from blown film extrusion plants. This film leaves the die head as film tube and is wound up either directly as a film tube or is severed into two film webs that are frequently wound up as double layers. In the following description these multi-layered material webs are also called layers of material webs. Film rolls are also known in which more than two material webs are wound up.
The reason for the afore-mentioned disadvantages is that at high winding speeds air gets trapped and is subsequently wound up in between the said film layers or in the film tubes. This gives rise to unattractive, too voluminous and telescopic film tubes, thus finally even causing the interruption of the winding processes. In case of film tubes, the shape of the initial section of the film during its transport through the winding device is referred to, partly metaphorically as “fish mouth.” Additional defects with regard to quality come into existence in case of too uneven and unattractive slits at the cutting point (while cutting off the film web perpendicular to its conveying direction) when air gets trapped between the layers that are to be cut. Even film tubes are referred to as multi-layered material webs in this patent application.
The objective of the present invention is to suggest a device that reduces the chances of air getting trapped in-between multi-layered, web-shaped material when the latter is being wound up.
This objective is achieved by
The ability of different layers of material to join one another with great stability when charged electrostatically is greatly surprising. Furthermore, it must be mentioned that for improving the initial winding process an electrical field can also be used on the winding core without any interference from the means according to the invention for electrostatically charging the web-shaped material.
In the sense of this invention a winding core can be a winding sleeve or a different body shaped like a rod or a circular cylinder.
In case of different types and sizes of winders, it is advantageous to insert the film at different mounting positions and distances from the winding sleeve along its transport path. However, in general, it is useful if the electrical field joins the film layers to one another before they reach the cutter.
In case of a contact winder, the roller that guides the film before it reaches the winding core is the contact roller.
The process of charging the film electrostatically while passing through the rollers has proved to be greatly valuable.
Modern winding devices often have a multitude of such suitable deflecting or web guide rollers. These can also be arranged upstream to the winding device on the transport path of the web-shaped material.
Additional preferred embodiments of the invention are specified in the present description and in the claims. The individual figures of the drawing illustrate:
a a section of the perspective view of the device illustrated in
b a view of the lock
The insert sheets 11 for inserting the winding sleeves 7 into the storage device 2, the linear cylinder 12, the knife protection 13 and the traverse member 14 can also be seen in
In the upper section of the holding arms, the holding heads 22 can be seen that can take over the winding shafts 7 from the storage device 1. In
The holding heads 22 can be displaced along the holding arms 16 in the vertical direction. In this manner the winding shaft 7 can be placed on the contact roller 18. This position 34 of the winding sleeve—the so-called initial winding position of the illustrated contact winder—is illustrated in
Additional details of the winding process and the transport of the winding shafts through a contact roller are known to those skilled in the art and hence do not require a more elaborate explanation.
The material web or the film 35 is illustrated only in the
Therefore
These means comprise of the electrode 38 and the mounting device 42. Above this deflecting roller 39, the last deflecting roller 37 is located upstream in the transport direction z of the web-shaped material. The outlined guiding of the deflecting roller is marked with the reference symbol 43. It can be provided with additional means for electrostatically charging the roller 39 in order to increase the potential difference of the electrode 38 or to provide the film with a potential independent of the electrode 38. The afore-mentioned blocking effect of the two tube walls according to the invention can also be achieved by the exclusive application of charge to the roller. The web-shaped material guided over the deflecting roller 39 comprises of the inner 40 and the outer 41 film web. Since the electrode is not charged, both the film webs 40, 41 diverge from one another. This divergence of the two film webs is somewhat exaggerated in the illustration.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10321599.9 | May 2003 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP04/04803 | 5/5/2004 | WO | 11/7/2005 |
